Answer:
18.33 ×10²³ atoms
Explanation:
Given data:
Molar mass of sulfuric acid = 98.1 g/mol
Mass of sulfuric acid = 75.0 g
Number of of oxygen atom present = ?
Solution:
Number of moles of sulfuric acid:
Number of moles = mass/molar mass
Number of moles = 75.0 g/ 98.1 g/mol
Number of moles =0.761 mol
one mole of sulfuric acid contain four mole of oxygen atom.
0.761 mol × 4 = 3.044 mol
1 mole = 6.022×10²³ atoms of oxygen
3.044 mol × 6.022×10²³ atoms of oxygen / 1mol
18.33 ×10²³ atoms
pH is equivalent to the negative log of the concentration of
H in molarity, that is:
pH = - log [H]
so the concentration is:
8.05 = - log [H]
[H] = 8.91 x 10^-9 M
the absolute error is:
8.07 = - log [H’]
[H’] = 8.51 x 10^-9 M
absolute error = 8.91 x 10^-9 M - 8.51 x 10^-9 M = 0.4 x
10^-9 M
Therefore:
<span>8.91 x 10^-9 M ± 0.4 x 10^-9 M</span>
Here we have to choose the atom which has same number of neutrons as 14N
The atom which has same number of neutrons as 14N among the given atoms is (D) 13C
We know, in an atom the number of electrons (atomic number) is equivalent to the number of protons. For nitrogen (N), the number of electron is 7. Thus the number of protons present in the nucleus is also 7 to make the atom uncharged.
The mass number of the atom is the number of the neutrons + number of the protons. In 14N there are 7 protons and 7 neutrons.
Thus among the given atoms the atom which has 7 neutrons will have the same number of neutrons.
A) Now in 16O the atomic number is 8 and mass number is 16. Thus the number of protons and neutrons are each 8 units.
B) In 15N, the atomic number is 7 but mass number is 15, thus number of protons and neutrons are 7 and 8 respectively.
C) In 14P the atomic number is 15 but mass number is 14, so number of protons and neutrons are 15 and -1 (not exist) respectively.
D) In 13C the atomic number is 6 and mass number is 13. So the number of protons are 6 and number of neutrons are 7.
Thus the correct answer will be D) 13C.
I think the answer is hydrosphere
